31163521 has 2 divisors, whose sum is σ = 31163522. Its totient is φ = 31163520.

The previous prime is 31163513. The next prime is 31163543. The reversal of 31163521 is 12536113.

It is a happy number.

It is an a-pointer prime, because the next prime (31163543) can be obtained adding 31163521 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19847025 + 11316496 = 4455^2 + 3364^2 .

It is an emirp because it is prime and its reverse (12536113) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31163521 - 2³ = 31163513 is a prime.

It is a super-2 number, since 2×31163521² = 1942330082234882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31163492 and 31163501.

It is not a weakly prime, because it can be changed into another prime (31163221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15581760 + 15581761.

It is an arithmetic number, because the mean of its divisors is an integer number (15581761).

Almost surely, 2^31163521 is an apocalyptic number.

It is an amenable number.

31163521 is a deficient number, since it is larger than the sum of its proper divisors (1).

31163521 is an equidigital number, since it uses as much as digits as its factorization.

31163521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 540, while the sum is 22.

The square root of 31163521 is about 5582.4296681642. The cubic root of 31163521 is about 314.6894428108.

Adding to 31163521 its reverse (12536113), we get a palindrome (43699634).

It can be divided in two parts, 31163 and 521, that added together give a square (31684 = 178²).

The spelling of 31163521 in words is "thirty-one million, one hundred sixty-three thousand, five hundred twenty-one".